[zakthor]

Originally Posted by john70t

I've read a little bit about Japanese Katana. 1,000 fold techniques. Quenching and adding carbon throughout the process. Not necessarily unique to them. Most mass-produced swords were probably not. What is amazing is the utilization of limited iron availability to work with back then.

Each advanced sword maker took a lifetime of secret knowledge to the grave...

One thing that stood out is the design of softer steel in the center, surrounded by the leading edge blade layer of hardened steel, which tends to be brittle.

The 'softer' inside center absorbs and spreads impact forces, while the 'harder' layer retains it's edge and rust resistance.

https://en.wikipedia.org/wiki/Wootz_steel